Sztochasztikus Rendszerek és Pénzügyi Piacok Modellezése = Stochastic Systems and Modelling of Financial Markets

A kutatások célja a sztochasztikus rendszerek legkorszerűbb módszereinek az alkalmazása a pénzügyi piacok modellezésében és maguknak a módszereknek a továbbfejlesztése. A pénzügyi matematika ma egyik legnagyobb kihívása jó fedezeti stratégiák kialakítása nem-teljes piacokon. Ez matematikailag egy sajátos sztochasztikus adaptív kontrol problémát jelent, ahol a dinamikát egy sokdimenziós switching diffúziós folyamat írja le. Ehhez az általános problémához számos részprobléma köthető. . Kutatásaink javarészt PhD hallgatók által is megoldható módszertani problémákhoz kötődnek. A fő területek: rejtett Markov-folyamatok, tőzsdemodellek, sztochasztikus volatilitás, valamint a kontroll elmélet és az opcióárazás kapcsolata. Ezen túl munkáinkban a sztochasztikus adaptív kontrol néhány alapvető kérdését is vizsgáltuk. | The objective of this research was to apply and develop advanced methods of stochastic systems for modelling financial markets. A current challenge in financial mathematics is the development of reliable hedging strategies for incomplete markets. Mathematically this is a stochastic asptive control problem in which the dynamics of the system is described by a multivariable switching diffusion process. This major problem could be related to a number of simpler problems. Most of our research topics were releated to technical problems that could be handled within the framework of a PhD program. The main areas were: hidden Markov models, models for a stock exchange, stochastic volatility and the relationship between stochastic control and option pricing. In addition we have studied a few fundamental problems of stochastic adaptiv control

Telített 1,3-heterociklusok gyűrű-lánc tautomériája - szubsztituenshatások vizsgálata, szintetikus alkalmazás = Ring-chain tautomerism of saturated 1,3-heterocycles - substituent effects, synthetic applications

Megállapítottuk, hogy az aminoalkil-naftolok és az aminoalkil-kinolinolok három komponensű, egylombikos Mannich-reakcióval történő előállításában az ammónium-karbamát és az ammónium-hidrogénkarbonát hatékony ammónia¬forrásként használható. Módosított Mannich reakciók során 1- és 2-naftolból illetve heterociklusos analógjaikból kiindulva számos új heterociklust állítottunk elő. Aminometilnaftolból dihidroizokinolinokkal, új pentaciklusos oxazinokat nyertünk. E közleményünket a Synfact folyóirat méltatta: http://www.thieme-connect.com/ejournals/toc/synfacts. Bizonyítottuk, hogy irodalmi adatokkal ellentétben a 2-amino-feniletanol és a 2-amino-fenilpropanol aromás aldehidekkel oldatfázisban háromkomponensű tautomer elegyet alkot. Új, környezetbarát eljárást fejlesztettünk ki spiropiperidinek előállítására. Megállapítottuk, hogy a 2-aminokarbohidrazidok és az 1-benzil-4-piperidon ciklizációja katalizátor nélkül, vízben is lezajlik, és az oldatból nagy tisztaságú termék kristályosodik ki. Nagyszámú 2,2-diszubsztituált kinazolin-4-on egyszerű, könnyen végrehajt¬ható szintézisét oldottuk meg „zöld” körülmények között vízben, vagy oldószer nélkül, 2-amino-karboxamidok ketonokkal történő gyűrűzárásával. Gyűrű-lánc tautomériát mutató közti terméken keresztül lezajlódó dominó reakcióval új típusú laktámok szintézisét oldottuk meg kiváló diasztereoszelektivitással. A kutatások során nemzetközi folyóiratokban összesen 23 közlemény jelent meg, melyek összimpakt faktora 47,6. | Ammonium carbamate and ammonium hydrogencarbonate were found to be very effective, solid sources of ammonia in the preparation of various aminoalkylnaphthols and aminoalkylquinolinols via one-pot Mannich reaction. By using a modified Mannich reaction, a great number of new heterocycles were prepared starting from 1- and 2-naphthol or their heterocyclic analogs. By reactions of aminomethylnaphthol and dihydroisoquinolines, new pentacyclic oxazines were formed. It was proved that in spite of the literature data, the condensation products of 2-aminophenylethanol or 2-aminophenylpropanol with aromatic aldehydes, participate in three-component tautomeric equilibria in solution. A new, environment-friendly process has been developed for the synthesis of spiropiperidines. The spirocyclizations of 2-aminocarbohydrazides and 1-benzyl-4-piperidone took place even in water under catalyst-free conditions, and the products crystallized out of the reaction mixture in pure form. An easy and green synthetic protocol has been developed for the preparation of 2,2-disubstituted quinazolin-4-one derivatives via ring-closures of 2-aminocarboxamides with ketones using water as solvent or solvent-free conditions. By the domino reactions of the corresponding ring-chain tautomeric intermediates, novel lactams were prepared with excellent diastereoselectivities. In frame of the research project, 23 publications (cumulative impact factor: 47.6) has been published in international scientific journals

Habitat Changes along Ipoly River Valley (Hungary) in Extreme Wet and Dry Years

The Ipoly Valley is a natural habitat along the Ipoly River, only slightly affected by water management; therefore, this is an especially sensitive area and reflects well the vegetation changes in the driest (2020) and wettest (2010) years. The study’s aim is to identify natural changes within habitats and the evaluation of habitat types’ boundaries. For the study, a hand-held GPS device was applied on-site. The habitat identification is based on the General National Habitat Classification System (Á-NÉR). In addition to on-site data, Sentinel-2A satellite data were used to compare different extreme years 2020 and 2021—changes in different habitat patches using different vegetation indices. A change in precipitation causes shifts in the vegetation, this is shown on a map. As we predicted, decreasing the precipitation results in a decrease of the area of wet habitat patches. The satellite image shows a more accurate picture of the real location of the associations, which is important for long-term research. In addition, we can get accurate data on the situation of areas (roads and paths) affected by anthropogenic factors

Habitat Changes along Ipoly River Valley (Hungary) in Extreme Wet and Dry Years

The Ipoly Valley is a natural habitat along the Ipoly River, only slightly affected by water management; therefore, this is an especially sensitive area and reflects well the vegetation changes in the driest (2020) and wettest (2010) years. The study’s aim is to identify natural changes within habitats and the evaluation of habitat types’ boundaries. For the study, a hand-held GPS device was applied on-site. The habitat identification is based on the General National Habitat Classification System (Á-NÉR). In addition to on-site data, Sentinel-2A satellite data were used to compare different extreme years 2020 and 2021—changes in different habitat patches using different vegetation indices. A change in precipitation causes shifts in the vegetation, this is shown on a map. As we predicted, decreasing the precipitation results in a decrease of the area of wet habitat patches. The satellite image shows a more accurate picture of the real location of the associations, which is important for long-term research. In addition, we can get accurate data on the situation of areas (roads and paths) affected by anthropogenic factors

Habitat Mosaics of Sand Steppes and Forest-Steppes in the Ipoly Valley in Hungary

The present study focuses on the mosaic-like occurrences of patches of steppes and fore-steppes in the Pannonian forest-steppe zone. We present the current vegetation, which is maintained including by human landscape use, i.e., grazing and mowing. The area is complex and for this reason it shows the changes in the landscape and differences in the vegetation more diversely. We wanted to answer the questions: Do sand steppes and forest-steppes occur in the Ipoly Valley and what location? What kind of environmental effects influence the species composition on these areas? Besides classic habitat mapping, are the satellite data from Sentinel-2A useful for distinction of different areas? Comparison of vegetation patches was based on the Hungarian habitat classification system (ÁNÉR). Based on satellite images, quantile data of the Normalized Vegetation Index (NDVI) were used for comparison. Based on the result, water bodies and urban areas are clearly distinguishable from other natural habitats. In some natural vegetation types, we found visible differences, such as grasslands, i.e., sandy steppe meadows and shrubby, woody vegetation patches. Sandy vegetation mainly grows on calcareous soils, which appear to be mosaic-like in the landscape on raised alluvials on the patches of past islands and reefs. From open to continuous closed grasslands, these vegetation types mainly grow on lithosoils. New occurrences of Pannonian sandy vegetation were discovered. In the sandy areas along the Ipoly Valley, open sandy grasslands were found, which is where the northernmost known occurrences of this vegetation type are. Besides common sandy grassland species, the vegetation also contains herbs that are typical in loess-grasslands and it is maintained by grazing, similarly to the eastern Pannonian area. This type of grazing can be useful when maintaining the mosaic-like appearance and diversity of the vegetation

Habitat Mosaics of Sand Steppes and Forest-Steppes in the Ipoly Valley in Hungary

The present study focuses on the mosaic-like occurrences of patches of steppes and fore-steppes in the Pannonian forest-steppe zone. We present the current vegetation, which is maintained including by human landscape use, i.e., grazing and mowing. The area is complex and for this reason it shows the changes in the landscape and differences in the vegetation more diversely. We wanted to answer the questions: Do sand steppes and forest-steppes occur in the Ipoly Valley and what location? What kind of environmental effects influence the species composition on these areas? Besides classic habitat mapping, are the satellite data from Sentinel-2A useful for distinction of different areas? Comparison of vegetation patches was based on the Hungarian habitat classification system (ÁNÉR). Based on satellite images, quantile data of the Normalized Vegetation Index (NDVI) were used for comparison. Based on the result, water bodies and urban areas are clearly distinguishable from other natural habitats. In some natural vegetation types, we found visible differences, such as grasslands, i.e., sandy steppe meadows and shrubby, woody vegetation patches. Sandy vegetation mainly grows on calcareous soils, which appear to be mosaic-like in the landscape on raised alluvials on the patches of past islands and reefs. From open to continuous closed grasslands, these vegetation types mainly grow on lithosoils. New occurrences of Pannonian sandy vegetation were discovered. In the sandy areas along the Ipoly Valley, open sandy grasslands were found, which is where the northernmost known occurrences of this vegetation type are. Besides common sandy grassland species, the vegetation also contains herbs that are typical in loess-grasslands and it is maintained by grazing, similarly to the eastern Pannonian area. This type of grazing can be useful when maintaining the mosaic-like appearance and diversity of the vegetation

Use of an integrated strip-free blood glucose monitoring system increases frequency of self-monitoring and improves glycemic control: Results from the ExAct study

Aims We investigated the impact of using an integrated, strip-free system compared to the use of single-strip systems on testing frequency and glycemic control in individuals with insulin-treated diabetes. Methods This multinational, comparative, cluster-randomized, observational study included 311 patients with type 1 and insulin-treated type 2 diabetes who were performing SMBG at suboptimal frequencies. Sites were cluster-randomized to “integrated strip-free” system (EXP group) or any “single-strip” system (CNL group). Testing frequency and HbA1c were measured at baseline, 12 weeks and 24 weeks. Results At week 24, the EXP group showed an increase in SMBG frequency from baseline of 4.17 tests/week (95% CI 2.76, 5.58) compared with an increase of 0.53 tests/week (95% CI −0.73, 1.79) among CNL patients, resulting in a between-group difference of 3.63 tests/week (p < 0.0002). Mixed-effects models for repeated measurements (MMRM) controlling for baseline frequency of testing, country and clinical site confirmed a higher SMBG testing frequency in the EXP group compared to the CNL group, with a between-group difference of 2.70 tests/week (p < 0.01). Univariate analysis showed greater HbA1c reductions in the EXP group than CNL group: −0.44% (95% CI −0.59, −0.29) vs. −0.13% (95% CI −0.27, 0.01), respectively, p < 0.0002. MMRM analyses confirmed these HbA1c reductions. A greater percentage of EXP than CNL patients achieved HbA1c reductions of ≥0.5%: 45.1% vs. 29.1%, respectively, p < 0.01. Conclusions The use of an integrated, strip-free SMBG system improved testing adherence and was associated with improvements in glycemic control

Use of an integrated strip-free blood glucose monitoring system increases frequency of self-monitoring and improves glycemic control: Results from the ExAct study

Aims: We investigated the impact of using an integrated, strip-free system compared to the use of single-strip systems on testing frequency and glycemic control in individuals with insulin-treated diabetes. Methods: This multinational, comparative, cluster-randomized, observational study included 311 patients with type 1 and insulin-treated type 2 diabetes who were performing SMBG at suboptimal frequencies. Sites were cluster-randomized to “integrated strip-free” system (EXP group) or any “single-strip” system (CNL group). Testing frequency and HbA1c were measured at baseline, 12 weeks and 24 weeks. Results: At week 24, the EXP group showed an increase in SMBG frequency from baseline of 4.17 tests/week (95% CI 2.76, 5.58) compared with an increase of 0.53 tests/week (95% CI −0.73, 1.79) among CNL patients, resulting in a between-group difference of 3.63 tests/week (p < 0.0002). Mixed-effects models for repeated measurements (MMRM) controlling for baseline frequency of testing, country and clinical site confirmed a higher SMBG testing frequency in the EXP group compared to the CNL group, with a between-group difference of 2.70 tests/week (p < 0.01). Univariate analysis showed greater HbA1c reductions in the EXP group than CNL group: −0.44% (95% CI −0.59, −0.29) vs. −0.13% (95% CI −0.27, 0.01), respectively, p < 0.0002. MMRM analyses confirmed these HbA1c reductions. A greater percentage of EXP than CNL patients achieved HbA1c reductions of ≥0.5%: 45.1% vs. 29.1%, respectively, p < 0.01. Conclusions: The use of an integrated, strip-free SMBG system improved testing adherence and was associated with improvements in glycemic control